[Gimp-user] help & gray threshold

[Thomas Widlar <twidlar yahoo com>]

1. I've just downloaded and installed GIMP and GIMP help system for
Win7. When I hover over the action buttons or options, I'm told to press
F1 for help, but no help comes up. What do I need to do sto connect GIMP
to its help.

2. My first task is to upgrade some music pages for a composer. He has
grayscale PDFs. The music scanned well but the horizontal staff lines
are a light grey, clear but light. How do I make any pixel darker than
certain threshold value black? How do I set that threshold?

I have no experience with GIMP, just some minimal experience with
MSPAINT. But I'm happy to learn.